Davyhulme Wastewater Treatment Works Modernisation Project
Davyhulme, Greater Manchester · 2015-2020 (AMP6 modernisation project); new 10-year plan with initial investment from 2025 [WaterProjectsOnline, United Utilities] · £187m (AMP6 modernisation project) [WaterProjectsOnline]; initial investment of around £350m over the next five years (from 2025) [United Utilities]
The judgement call
Account-gated at launchPioneering the activated sludge process in 1914 [WaterProjectsOnline, United Utilities] - Extensive use of BIM (4D visualisation) and DfMA (Design for Manufacture and Assembly) for time, cost, and safety benefits [WaterProjectsOnline, Arcadis] - Delivered AMP6 project ahead of schedule and within budget [WaterProjectsOnline] - Strong focus on health and safety, achieving over 1,500,000 hours without a RIDDOR incident [WaterProjectsOnline]
Key engineering challenges
Modernising one of Europe's oldest and largest wastewater treatment works while keeping it fully operational [Arcadis] - Achieving compliance with a more stringent final effluent ammonia (NH3) discharge consent of 1 mg/l [WaterProjectsOnline] - Meeting the demand of exponential population growth and the impact of climate change [WaterProjectsOnline] - Building on land historically used to stockpile waste, requiring remediation [WaterProjectsOnline]
Project facts
- Client / owner
- United Utilities
- Lead contractor
- Laing O’Rourke (for AMP6 modernisation project) [WaterProjectsOnline]; United Utilities Enterprise delivery model (seven design and construction partners) for the new 10-year plan [United Utilities]
- Lead designers
- Arcadis in a joint venture with Mott MacDonald (for AMP6 modernisation project) [Arcadis]
- Project type
- upgrade | modernisation
- Scale
- Serves over 1.3 million customers [WaterProjectsOnline]; Incoming flows up to 30m³/s, flow to full treatment 8.36m³/s [WaterProjectsOnline]; Ten-lane Activated Sludge Plant (175m x 110m x 8m deep) [WaterProjectsOnline]; 6 (No.) 41m diameter primary settlement tanks (PSTs), 10 (No.) 46m diameter final settlement tanks (FSTs) [WaterProjectsOnline]
- Disciplines
- Civil; structural; geotechnical; process; mechanical; electrical; environmental; digital engineering
- Standards & frameworks
- AMP6; National Environment Programme (NEP); Freshwater Fish Directive; Water Framework Directive; CDM Regulations; Environmental Agency regulations
Sources: WaterProjectsOnline: https://waterprojectsonline.com/case-studies/davyhulme-2019/ (Accessed: 2026-06-10) - Arcadis: https://www.arcadis.com/en-gb/projects/europe/united-kingdom/davyhulme-wastewater-treatment-works (Accessed: 2026-06-10) - United Utilities: https://www.unitedutilities.com/corporate/newsroom/latest-news/ten-year-plan-to-transform-davyhulme-wastewater-treatment-works/ (Accessed: 2026-06-10) - ICE: https://www.ice.org.uk/what-is-civil-engineering/infrastructure-projects/davyhulme-wastewater-treatment-works (Accessed: 2026-06-10)